Study Design: This is descriptive analytical study. Purpose: The present study aims at comparing treatment results found between the two groups comprising of patients who underwent posterior spinal fusion using thoracic pedicle screws and the ones who underwent combined anterior-posterior method, respectively. Overview of Literature: There was controversy about surgical techniques including anterior, posterior, or a combined anterior-posterior approaches are applied to treat non-congenital scoliosis with surgical indications. Methods: Medical records of 50 patients suffering from thoracic non-congenital scoliosis with curves exceeding 70° were reviewed. In this study, 25 patients who underwent posterior spinal fusion using thoracic pedicle screws were compared with 25 patients who underwent combined anterior-posterior method. Results: Patients treated through posterior-only and combined approaches were respectively hospitalized for 11.84±5.18 and 26.5±5.2 days (p=0.001). There was a significant difference between these two groups considering intensive care unit admission duration (p=0.001), correction in sagittal view of X-ray (p=0.01), and number of days the patients underwent traction (0.001). Finally, coronal view was corrected without any significant difference (p=0.2). Conclusions: According to our findings, it is hypothesized that posterior-only method is associated with some significant advantages and is an advisable method in patients with severe scoliosis over than 70°.